title: Experimental and computational studies of anti-Bredt amidinium salts.
abstract: Experimental and computational investigations of anti-Bredt amidinium salts are presented. Calculations show that the pyramidalization of an amino group can significantly destabilize the formal carbocation center of amidiniums, due to the decreased π donation. In some cases, the unfavorable -I effect of nitrogen surpasses its beneficial +M effect, and amidiniums become less stable than iminiums. It is shown that although 1-aza-3-azonia[3.3.1]bicyclo-non-2-enes can be isolated, they feature a nonclassical reactivity, which is more typical for iminium than amidinium salts, such as pronounced electrophilicity and azomethineylide instead of carbene formation.
authors.affiliation: UCSD-CNRS Joint Research Laboratory (UMI 3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093 0343 (USA).
authors.forename: David
authors.initials: D
authors.lastname: Martin
authors.forename: Nicolas
authors.initials: N
authors.lastname: Lassauque
authors.forename: Florian
authors.initials: F
authors.lastname: Steinmann
authors.forename: Gerald
authors.initials: G
authors.lastname: Manuel
authors.forename: Guy
authors.initials: G
authors.lastname: Bertrand
keywords: azomethineylides; carbenes; carbocations; strained molecules; substituent effects